scholarly journals Small mammal assemblage in beaver-modified habitats

2020 ◽  
Author(s):  
Janne Sundell ◽  
Wenfei Liao ◽  
Petri Nummi
Keyword(s):  
Small Mammal ◽  
Boreal Forests ◽  
Ecosystem Engineer ◽  
Castor Canadensis ◽  
Regional Scale ◽  
Common Species ◽  
Habitat Diversity ◽  
Myodes Glareolus ◽  
Positive Interactions ◽  
The North

Abstract One of the less studied positive interactions among organisms is facilitation. Facilitation may have significant impact on diversity of species especially in low productive environments. We studied the effects of well-known facilitator and ecosystem engineer, the North American beaver (Castor canadensis), on small mammal assemblages in the boreal zone. The small mammals, namely voles, mice, and shrews, were trapped over 2 years in ten beaver-modified habitats and in ten control sites. Contrary to our expectations, we did not observe any differences between species or individual numbers between beaver-modified and control sites. However, there were differences in species composition between sites; grass-eating field voles (Microtus agrestis) and invertebrate-eating shrews (Sorex araneus, Neomys fodiens) tended to be more common in beaver sites while forest-dwelling wood lemmings (Myopus schisticolor) and yellow-necked mice (Apodemus flavicollis) were only captured in control sites. The most common species in both habitats was the bank vole (Myodes glareolus), which is a generalist in its habitat requirements. The bank vole’s population structures were similar between the two habitat types. The actions of beavers in water bodies within boreal forests seem to have no effect on the small mammal diversity and their numbers at the regional scale but may have positive effect on them at the larger landscape level as beavers are increasing the overall habitat diversity in the landscape.

Intrinsic and extrinsic factors in the dynamics of local small-mammal populations

2010 ◽  
Vol 88 (2) ◽  
pp. 178-185 ◽  
Author(s):  
T. Solonen ◽  
P. Ahola
Keyword(s):  
Small Mammal ◽  
Large Scale ◽  
Population Decline ◽  
Clethrionomys Glareolus ◽  
Myodes Glareolus ◽  
Small Scale ◽  
Extrinsic Factors ◽  
Related Factors ◽  
The North ◽  
The North Atlantic Oscillation

We studied dynamics of local small-mammal assemblages consisting of shrews, voles, and mice by small-scale snap trapping in each spring and autumn from 1981 to 2006 in southern Finland. Our aim was to search for relative roles of possible regulatory associations within and between species, as well as to find reflections of the effects of large-scale climatic phenomena on local populations. Preceding intraspecific densities had a dominating role in seasonal changes in small-mammal numbers. Their relationships with weather-related factors indicated by the indices of the North Atlantic Oscillation (NAO) were most pronounced during winter. Relationships with the NAO indices, increasing values of which indicate milder weather in the north, were negative in voles but positive in shrews and mice. Spring densities were governed by the largely compensatory effects of the growth rate of the preceding summer and subsequent population decline during winter in the field vole ( Microtus agrestis (L., 1761)) and mice, while the effects of winter decline dominated in shrews. The bank vole ( Myodes glareolus (Schreber, 1780) = Clethrionomys glareolus (Schreber, 1780)) showed decreasing winter decline, which had a considerable positive effect on population densities.

scholarly journals Dynamics of Territorial Occupation by North American Beavers in Canadian Boreal Forests: A Novel Dendroecological Approach

Forests ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 221 ◽  
Author(s):  
Julie-Pascale Labrecque-Foy ◽  
Hubert Morin ◽  
Miguel Montoro Girona
Keyword(s):  
Boreal Forest ◽  
North American ◽  
Water Body ◽  
Boreal Forests ◽  
Castor Canadensis ◽  
Natural Disturbance ◽  
Water Levels ◽  
The North ◽  
Patterns Of Use ◽  
Over Time

Research Highlights: Our study highlights a new, simple, and effective method for studying the habitat use by beavers in Canadian boreal forests. Information regarding the presence of beaver colonies and their habitat occupation is essential for proper forest management and damage prevention in the boreal forest. Background and Objectives: The North American beaver (Castor canadensis) is a major element of natural disturbance, altering the dynamics and structure of boreal forest landscapes. Beaver-related activities also affect human infrastructure, cause floods, and lead to important monetary losses for forestry industries. Our study aimed to determine the spatiotemporal patterns of beaver occupation of lodges over time. Materials and Methods: Using a dendroecological approach to date browsing activity, we studied the occupation of two lodges per water body for eight water bodies located in the boreal forest of Québec, Canada. Results: Three sites showed alternating patterns of lodge use (occupation) over time, three sites (37.5%) demonstrated no alternating patterns of use, and two sites (25%) presented unclear patterns of lodge use. Conclusions: Alternating patterns of lodge use can be linked to food depletion and the need to regenerate vegetation around lodges, while non-alternating patterns may be related to fluctuations in water levels, the specific shrub and tree species surrounding the lodges, the size of the beaver territory, and the number of lodges present on a water body.

Enhanced Seasonal Exchange of CO2 by Northern Ecosystems Since 1960

Science ◽  
2013 ◽  
Vol 341 (6150) ◽  
pp. 1085-1089 ◽  
Author(s):  
H. D. Graven ◽  
R. F. Keeling ◽  
S. C. Piper ◽  
P. K. Patra ◽  
B. B. Stephens ◽  
...  
Keyword(s):  
Boreal Forests ◽  
Atmospheric Carbon Dioxide ◽  
Ecosystem Models ◽  
The North ◽  
Ecological Changes ◽  
Term Change ◽  
Major Shift ◽  
Underlying Mechanisms ◽  
Global Carbon

Seasonal variations of atmospheric carbon dioxide (CO2) in the Northern Hemisphere have increased since the 1950s, but sparse observations have prevented a clear assessment of the patterns of long-term change and the underlying mechanisms. We compare recent aircraft-based observations of CO2 above the North Pacific and Arctic Oceans to earlier data from 1958 to 1961 and find that the seasonal amplitude at altitudes of 3 to 6 km increased by 50% for 45° to 90°N but by less than 25% for 10° to 45°N. An increase of 30 to 60% in the seasonal exchange of CO2 by northern extratropical land ecosystems, focused on boreal forests, is implicated, substantially more than simulated by current land ecosystem models. The observations appear to signal large ecological changes in northern forests and a major shift in the global carbon cycle.

scholarly journals Influence of the North Atlantic oscillation on the atmospheric levels of benzo[a]pyrene over Europe

2021 ◽  
Author(s):  
Pedro Jiménez-Guerrero ◽  
Nuno Ratola
Keyword(s):  
Spatial Pattern ◽  
North Atlantic Oscillation ◽  
North Atlantic ◽  
Transport Model ◽  
Regional Scale ◽  
The South ◽  
Climatic Fluctuations ◽  
The North ◽  
The North Atlantic ◽  
The North Atlantic Oscillation

AbstractThe atmospheric concentration of persistent organic pollutants (and of polycyclic aromatic hydrocarbons, PAHs, in particular) is closely related to climate change and climatic fluctuations, which are likely to influence contaminant’s transport pathways and transfer processes. Predicting how climate variability alters PAHs concentrations in the atmosphere still poses an exceptional challenge. In this sense, the main objective of this contribution is to assess the relationship between the North Atlantic Oscillation (NAO) index and the mean concentration of benzo[a]pyrene (BaP, the most studied PAH congener) in a domain covering Europe, with an emphasis on the effect of regional-scale processes. A numerical simulation for a present climate period of 30 years was performed using a regional chemistry transport model with a 25 km spatial resolution (horizontal), higher than those commonly applied. The results show an important seasonal behaviour, with a remarkable spatial pattern of difference between the north and the south of the domain. In winter, higher BaP ground levels are found during the NAO+ phase for the Mediterranean basin, while the spatial pattern of this feature (higher BaP levels during NAO+ phases) moves northwards in summer. These results show deviations up to and sometimes over 100% in the BaP mean concentrations, but statistically significant signals (p<0.1) of lower changes (20–40% variations in the signal) are found for the north of the domain in winter and for the south in summer.

A multiproxy record of sedimentation, pedogenesis, and environmental history in the north of West Siberia during the late Pleistocene based on the Belaya Gora section

2020 ◽  
pp. 1-19
Author(s):  
Vladimir Sheinkman ◽  
Sergey Sedov ◽  
Lyudmila S. Shumilovskikh ◽  
Elena Bezrukova ◽  
Dmitriy Dobrynin ◽  
...  
Keyword(s):  
Environmental History ◽  
Boreal Forests ◽  
West Siberia ◽  
Northern Eurasia ◽  
Partial Recovery ◽  
Radiocarbon Dates ◽  
Oxygen Isotope Stage ◽  
Mis 3 ◽  
The North ◽  
Mis 5

Abstract Recent revision of the Pleistocene glaciation boundaries in northern Eurasia has encouraged the search for nonglacial geological records of the environmental history of northern West Siberia. We studied an alluvial paleosol-sedimentary sequence of the high terrace of the Vakh River (middle Ob basin) to extract the indicators of environmental change since Marine Oxygen Isotope Stage (MIS) 6. Two levels of the buried paleosols are attributed to MIS 5 and MIS 3, as evidenced by U/Th and radiocarbon dates. Palynological and pedogenetic characteristics of the lower pedocomplex recorded the climate fluctuations during MIS 5, from the Picea-Larix taiga environment during MIS 5e to the establishment of the tundra-steppe environment due to the cooling of MIS 5d or MIS 5b and partial recovery of boreal forests with Picea and Pinus in MIS 5c or MIS 5a. The upper paleosol level shows signs of cryogenic hydromorphic pedogenesis corresponding to the tundra landscape, with permafrost during MIS 3. Boulders incorporated in a laminated alluvial deposit between the paleosols are dropstones brought from the Enisei valley by ice rafting during the cold MIS 4. An abundance of eolian morphostructures on quartz grains from the sediments that overly the upper paleosol suggests a cold, dry, and windy environment during the MIS 2 cryochron.

Small mammal mycophagy in hemiboreal forest communities of Lithuania

2011 ◽  
Vol 6 (3) ◽  
pp. 446-456 ◽  
Author(s):  
Marija Kataržytė ◽  
Ernestas Kutorga
Keyword(s):  
Small Mammals ◽  
Small Mammal ◽  
Fungal Spores ◽  
Seasonal Effects ◽  
Deciduous Tree ◽  
Myodes Glareolus ◽  
Mammal Species ◽  
Hypogeous Fungi ◽  
Fecal Samples ◽  
Significant Difference

AbstractThe diets of small mammals in different hemiboreal spruce-dominated, oak-dominated and mixed forests in western part of Lithuania were studied by examination of fungal spores in fresh fecal pellets of caught animals. In the diets of mice (Apodemus spp.), bank voles (Myodes glareolus), and common and pygmy shrews (Sorex araneus and S. minutus), 22 different fungal taxa were identified, 15 of which were hypogeous fungi. The sporocarp abundance and the spores in fecal samples of Elaphomyces fungi prevailed in study area during this investigation. Although most of the captured individuals consumed fungi, the consumption varied among small mammal species. The data show that the fungi were more frequent and taxonomically diverse in Myodes glareolus than in Apodemus spp. diets. The study provided evidence that the fungal component in the diets of insectivorous Sorex species is more diverse than previously known. The availability of sporocarps and the fungal component in the diets of small mammals showed seasonal effects. Annual hypogeous and epigeous sporocarp abundances did not vary significantly across forest types. The significant difference in mycophagy was observed across all forest cover types, with the greatest fungal diversity in fecal samples collected in mixed coniferous-deciduous tree stands.

scholarly journals Small-mammal assemblages inhabiting Sphagnum peat bogs in various regions of Poland

2012 ◽  
Vol 49 (2) ◽  
pp. 115-133
Author(s):  
Mateusz Ciechanowski ◽  
Jan Cichocki ◽  
Agnieszka Ważna ◽  
Barbara Piłacińska
Keyword(s):  
Small Mammal ◽  
Western Europe ◽  
Habitat Degradation ◽  
Myodes Glareolus ◽  
Peat Bogs ◽  
Trophic Conditions ◽  
Characteristic Features ◽  
Mammal Assemblages ◽  
Sorex Minutus ◽  
Pygmy Shrew

Abstract We studied species composition of assemblages of small mammals (rodents and shrews) inhabiting Polish 25 ombrotrophic mires and quaking bogs in several regions in order to reveal characteristic features of their quantitative structure and compare them between regions, internal zones of the bog habitats, and different levels of anthropogenic degradation. We reviewed also all published results of small-mammal trapping in such habitats. Mammals were captured in pitfalls, snap traps and live traps on 12 bogs of the Pomerania region, 4 bogs of the Orawa-Nowy Targ Basin (Kotlina Orawsko-Nowotarska), 3 bogs in the Świętokrzyskie Mts, and 6 bogs in Wielkopolska and the Lubusz Land. Additionally, we included materials collected from Barber traps (pitfalls) used during studies of epigeic invertebrates on 4 bogs. In total, 598 individuals of 12 species were collected. The number of pitfall captures per 100 trapnights was very low (7.0-7.8), suggesting low population density. Shrews predominated among mammals captured in pitfalls, and the assemblage structure appeared to be similar to impoverished forest fauna, slightly enriched with ubiquitous species from meadows and agroecosystems, with a very small percentage of typical wetland species (Neomys fodiens, Neomys anomalus, Microtus oeconomus). Rodents (mostly Myodes glareolus) predominated only in samples obtained by live and snap traps. Pygmy shrew Sorex minutus was the most numerous species at most sites, sometimes being the only small mammal in that habitat, especially in well-preserved, treeless parts of bogs, dominated by Sphagnum peatmoss. The dominance and high constancy of S. minutus appear to be a characteristic feature of small-mammal assemblages inhabiting ombrotrophic mires, at least in some regions of Central and Western Europe. Enrichment of the fauna with other species might be related to either improved trophic conditions (by contact with mineralized ground waters) or habitat degradation (by peat mining, drainage, and subsequent secondary succession).

Diversity and distribution of large branchiopods in Kiskunság (Hungary) in relation to local habitat and spatial factors: implications for their conservation

2008 ◽  
Vol 59 (10) ◽  
pp. 940 ◽  
Author(s):  
Liesbet Boven ◽  
Bram Vanschoenwinkel ◽  
Els R. De Roeck ◽  
Ann Hulsmans ◽  
Luc Brendonck
Keyword(s):  
Species Richness ◽  
Hot Spot ◽  
Local Environment ◽  
Common Species ◽  
Habitat Diversity ◽  
Ecological Knowledge ◽  
Species Dispersal ◽  
Local Conditions ◽  
Spatial Factors ◽  
Large Branchiopods

Large branchiopods are threatened worldwide by the loss and degradation of their temporary aquatic habitats owing to drainage and intensive agriculture. Sound ecological knowledge of their diversity and distribution is a prerequisite to formulate effective conservation measures. In the present study, large branchiopods were collected from 82 temporary freshwater pools belonging to five habitat types in Kiskunság (Hungary). Dormant propagule bank analysis complemented the field survey. Eleven species were found, with large branchiopods occurring in more than half of the study systems. The high regional species richness and occurrence frequency of large branchiopods make Kiskunság a true ‘hot spot’ of large branchiopod diversity. The local environment was more important than spatial factors (isolation) in explaining the presence of the most common species. Dispersal was most likely not limiting for the large branchiopods in the study area and colonisation success of different species was differentially affected by local conditions, possibly invertebrate predation risk and hydroperiod. Meadow pools and wheel tracks contributed most to regional species richness through the presence of rare and exclusive species. To conserve branchiopod diversity, we stress the importance of high habitat diversity in the landscape and the need to conserve neglected habitats such as wheel tracks.

Metamorphic Gradient: A Regional-Scale Area Selection Criterion for Gold in the Northeastern Superior Province, Eastern Canadian Shield

SEG Discovery ◽  
2007 ◽  
pp. 1-15
Author(s):  
Michel Gauthier ◽  
Sylvain Trépanier ◽  
Stephen Gardoll
Keyword(s):  
Regional Scale ◽  
Selection Criterion ◽  
Superior Province ◽  
James Bay ◽  
Area Selection ◽  
The North ◽  
First Pass ◽  
Abitibi Subprovince ◽  
Frontier Region ◽  
Metamorphic Gradient

ABSTRACT One hundred years after the first gold discoveries in the Abitibi subprovince, the Archean James Bay region to the north is experiencing a major exploration boom. Poor geologic coverage in this part of the northeastern Superior province has hindered the application of traditional Abitibi exploration criteria such as crustal-scale faults and “Timiskaming-type” sedimentary rocks. New area selection criteria are needed for successful greenfield exploration in this frontier region, and the use of steep metamorphic gradients is presented as a possible alternative. The statistical robustness of the metamorphic gradient area selection criterion was confirmed by using the curve of the receiver operating characteristic (ROC) to estimate the correlation between metamorphic fronts and the distribution of known Abitibi orogenic gold producers. The criterion was then applied to the James Bay region during a first-pass craton-scale exploration program. This was part of the strategy that led to the discovery of the Eleonore multimillion-ounce gold deposit in 2004.

scholarly journals Climate impact on the development of Pre-Classic Maya civilisation

2018 ◽  
Vol 14 (8) ◽  
pp. 1253-1273 ◽  
Author(s):  
Kees Nooren ◽  
Wim Z. Hoek ◽  
Brian J. Dermody ◽  
Didier Galop ◽  
Sarah Metcalfe ◽  
...  
Keyword(s):  
North Atlantic ◽  
Agricultural Intensification ◽  
Climatic Variability ◽  
Regional Scale ◽  
Climate Impact ◽  
Classic Period ◽  
Beach Ridge ◽  
Maya Lowlands ◽  
The North ◽  
The Impact

Abstract. The impact of climate change on the development and disintegration of Maya civilisation has long been debated. The lack of agreement among existing palaeoclimatic records from the region has prevented a detailed understanding of regional-scale climatic variability, its climatic forcing mechanisms and its impact on the ancient Maya. We present two new palaeo-precipitation records for the central Maya lowlands, spanning the Pre-Classic period (1800 BCE–250 CE), a key epoch in the development of Maya civilisation. A beach ridge elevation record from world's largest late Holocene beach ridge plain provides a regional picture, while Lake Tuspan's diatom record is indicative of precipitation changes at a local scale. We identify centennial-scale variability in palaeo-precipitation that significantly correlates with the North Atlantic δ14C atmospheric record, with a comparable periodicity of approximately 500 years, indicating an important role of North Atlantic atmospheric–oceanic forcing on precipitation in the central Maya lowlands. Our results show that the Early Pre-Classic period was characterised by relatively dry conditions, shifting to wetter conditions during the Middle Pre-Classic period, around the well-known 850 BCE (2.8 ka) event. We propose that this wet period may have been unfavourable for agricultural intensification in the central Maya lowlands, explaining the relatively delayed development of Maya civilisation in this area. A return to relatively drier conditions during the Late Pre-Classic period coincides with rapid agricultural intensification in the region and the establishment of major cities.

Sign in / Sign up

Export Citation Format

Share Document